Add the R generic "toString" to "jobjRef" methods

[rikivillalba]

This is a feature request:
Sometimes I use to add a method for "jobjRef" to the generic base R toString(x, ...) and map it to java's object toString
It can made possible to use the |> pipe and otherwise save code or prevent the use of reflection for such a basic action as x$toString()

I think in somewhat like:

setMethod("toString", "jobjRef", function(x, ...) .jcall(x, "S", "toString"))

migth work.

Best regards.